
The Twelve Divisions of the Mahayana Canon are:
1) Sutra – the Buddha’s sermons.
2) Geya – metrical pieces.
3) Gatha – poems or chants.
4) Nidana – sutras written by request, or in answer to a specific questions – often involving precept breaking.
5) Itivrttaka – narratives.
6) Jataka – former lives of the Buddha.
7) Adbhuta-dharma – miracles.
8) Avadana – parables and metaphors.
9) Upadesa – question and answer discourses.
10) Udana – impromptu or unsolicited addresses.
11) Vaipulya – expanded sutras.
12) Vyakarana – prophecies.
(Source: Empty Cloud: Translated by Charles Luk & Revised by Richard Hunn, Element Books, (1988), Footnote 2, 189-190)